Metal containing trisazo dyes



UNITED STATES PATENT OFFICE METAL CONTAINING TRISAZO DYES Hans Krzikalla and Walter Limbacher, Ludwigshafen-on-the-Rhine,

Germany, assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application July 21, 1937, Serial No. 154,758. In Germany July 31, 1936 7 Claims.

The present invention relates to azo dyestuffs. We have found that valuable new azo dyestuffs are obtained by preparing complex metal compounds .of water-soluble polyazo dyestuffs of the general formula:

wherein the As are radicals of the benzene series at least one of which contains in ortho-position a hydroxyl group, A1 is the radical of a naphthol sulphonic acid, and A2 is an aromatic radical capable of coupling at least twice.

In the preparation .of the said polyazo dyestuffs a it is preferable to start from a diazotized orthoaminophenol or a diazotized ortho-aminobenzoic acid, as for example l-hydroxy-2-amino-4.6-dinitrobenzene, 1-hydroxy-2-amin.obenzene-4-sulphonic acid, 1-hydroxy-2-amino-5-nitrobenzene, 1 hydroxy-2-aminol-nitrobenzene-6-sulphonic acid, 7 phonic acid,

1-hydroxy-2-amino-4 -ch1orbenzene-6-sull-methyl-3amino-4-hydroxybenzene-fi-sulphonic acids, 5-nitro-2-amin0benzenel-carboxylic acid or 1-amino-2-naphthol-4-sulphonic acid, the diazo compound being coupled with an aminonaphthol sulphonic acid capable of coupling in ortho-position to the hydroxyl group and capable of still further diazotization, as for example 1.8-aminonaphthol-4- or -5-sulphonic acid, 2.8 aminonaphthohfi-sulphonic acid, 2.5- aminonaphthol-7 sulphonic acid or 1.8-aminonaphthol-3.6- or -4.6-disu1phonic acid.

As the component A2 there may be mentioned for example 1.3-dihydroxybenzene, 1.3.5-trihydroxybenzene, 1.3 diarninobenzene, 1.5 dihydroxynaphthalene,

1 hydroxy-B-aminobenzene and their derivatives capable of coupling at least twice.

aminesalready containing an azo bridge.

The

conversion into the complex metal compounds is effected by treatment of the polyazo dyestuffs free from metal with iron, chromium, nickel, cobalt, copper or other heavy metal compounds. The metal-containing dyestuffs according to this invention usually yield on leather dyeings which have very good fastness to acids, alkalies,

Washing and light.

Especially valuable niggrbrown shades of color are obtained with the complex iron compounds.

The following examples will further illustrate how the said invention may be carried out in practice but the invention is not restricted to these examples.

Example 1 A solution of 88 parts of the azo dyestuff l-hydroxya-aminol.6-dinitrobenzenel-amino-tnitrobenzene disulphonicacid-- l.3

-dihydroxybenzene in 1500 parts of water is mixed with parts of sodium acetate and about 16.2 parts of ferric chloride and boiled for some time. The complex iron compound formed is then salted out with common salt, filtered off by suction, washed and dried.

Neutralized chrome leather is dyed in a dyebath with a bath ratio of 1:4 which contains from 1 to 3 per cent of the said complex iron compound for from about 20 to 30 minutes at from to C. After adding about 2 per cent of sulphonated neats-foot oil, dyeing is continued for a further 30 minutes and the leather is then rinsed and worked up in the usual manner. A leather is obtained which is dyed nigger-brown shades having very good fastness to washing and light. If the chromium, nickel, cobalt or copper compounds of the dyestuff be used instead of the iron compound, valuable brown dyeings are also obtained.

l.8-aminonaphthol-3.6-]

, Example 2 A solution of 95.2 parts of the azo dyestuff 1-hydroxy-2-amino-4-nitrobenzenel.8-aminonaphthol-4.6-

fi-sulphonic acid l-amino-4-nitrobenzene fi-trioxybenzene is mixed with 45 parts of crystallized sodium acetate and 17 parts of ferric chloride and boiled for about 1 hour. The complex iron compound is then isolated in the manner described in Example 1.

Glace leather which has been pretreated in the usual manner is dyed for 2 hours at from 40 to 50 C. in a dyebath with a bath ratio of 1:200 with from 1 to 3 per cent of the said complex iron compound. A suspension of egg yolk in water is then added and, after each dyeing period of 30 minutes, acid and 1 per cent of chromium acetate are added. The leather thus dyed is rinsed and further worked up in the usual manner. A beautiful brown dyeing fast to washing is obtained.

The glace leather may also be dyed in the usual manner brushing on with a dyestuff solution.

The following list gives a number of other disulphonic acidl.3.]

complex metal azo dyestuffs which may be precombined with the azo group in the position pared according to this invention, together with marked 2:. the shade of color obtainable therewith:

3. A complex metal compound of an azo dye- Dlazotlzableingrffiazo dyestufi Middle component A2 Other component A Metal Shade of color 1-hydroxy-2-amino- 4.6 -dinitro- LB-dihydroxyhenzena 4-nitro-l-hydroxy-2:amino- Chromium. Brown.

benzene- 1.8-aminonaphtholbenzene-B-sulphomc acid. 3.6-disulphonic acid. I

Do Nigger-brown.

Brown. Do. Do.

2-chlor-l mlnobcnzene-fi- Nigger-brown.

sulphonic acid.

0 Brown. DO. H... (L-"- 7 Do. l-hydroxy m n 3.4-d1chlor-l-a nobenzene- Nigger-brown.

bcnzcnel.S-aminonaphthol- 6-sulphon1c acid. 4.6-disulphonic acid.

D0 Brown. Do. Do. phonic acld. 1-hydroxy-2-amino4-nitroben- 1.3-dihydroxybenzene. 4chlor-1-am1nobenzene d D zene-fi-sulphonic acid?1.8- aminonaphthol 3.6 dlsulphonic acid. 7

D d0 ..d0 Cobalt Do .do "C10 Nickel D0.

What we claim is:

1. A complex metal compound of an azo dyestufi of the general formula (SOaHh wherein one A is a nitrophenyl radical and the other A the wherein one A is a radical of the benzene series and the other A is the combined with the azo group in the position radical I No;

combined with the azo group in the position marked x.

'4. A complex metal compound of the azo dyestuiT having the formula 03H SOaH radical stuff of the general formula SOaH the other A the radical wherein one A is a radical of the benzene series and the other A is the radical combined with the azo group in the position marked :c.

wherein one A is a. para-nitrophenyl radical and 5. The complex iron compound of the azo dyestuff having the formula wherein one A is a para-nitrophenyl radical and the other A the radical HO- N02 combined with the azo group in the position marked 1:.

6. The complex copper compound of the azo dyestufi having the formula J wherein one A is a para-nitrophenyl radical and the other A the radical.

combined with the azo group in the position marked at.

7. The complex chromium compound of the azo dyestulf having the formula S6311 \SOBH wherein one A is a para-nitrophenyl radical and the other A the radical 

